


thermoregulation

by janigkale



Category: Big Hero 6 (2014)
Genre: Alive!Tadashi...I guess, Fevers, Fluff, Gen, Hamada bros, Overworking, Post-Big Hero 6 (2014), SFIT, Sickfic
Language: English
Status: Completed
Published: 2018-06-26
Updated: 2018-06-26
Packaged: 2019-05-29 00:54:44
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,915
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15061517
Author URL: https://archiveofourown.org/users/janigkale/pseuds/janigkale
Summary: Hiro spends way too much time in the lab, and if his brother doesn't  find out, that would be great. Obviously, things never work out.OrA good old sickfic with Hiro and Tadashi because who doesn’t want more of the Hamada Bros?





	thermoregulation

**Author's Note:**

> I recently rediscovered my obsession with Big Hero 6, ever since it came out four years ago. I love Hiro and Tadashi, and tried to put my own twist on a sickfic. Thanks for reading!

Hiro found robotic work comforting- it was constant, unpredictable, and something that he was particularly good at. So, if sometimes, he ended in the lab a little bit longer than necessary, a little being five hours longer, it wasn’t an issue. Even if he _maybe_ had gotten sick over the week and had told no one. He had GoGo and Fred for an endless Red Bull and coffee supply, however cautious they seemed to give it to him.

Case in point:

“I _just_ need to finish up my comments on the code, and then I’ll go home-“ GoGo rolled her eyes, gave him a canister.

“Your brother’s going to kick both our asses, you know?” She warned, eyes slitted, but Hiro, happy with his energy drink, dawdled back into his shared lab.

Somewhere in the distance, he heard Fred wistfully saying, “That’d be a pretty great panel- Tadashi going all Hulk-“ and he couldn’t help but snicker.

Tadashi, as of now, was in his Biomedical Signals and Controls classes, which was probably the only freaking reason that Hiro could have gotten away with staying at the lab so late. It wasn’t his fault his brother showed his feathers like the mother hen he was if he saw ever so much saw Hiro sniffle. It wasn’t. He’d sneak back to the Lucky Cat, all snug and curled up in his bed, trying not sniffle or sneeze, just until he heard the _squeak, squeak_ of Tadashi’s old mint green Converse and the comforting _whoosh_ of his brother’s light snores.

It had worked.

Honey Lemon had come by earlier with bubble tea and cupcakes and a new idea for hybrid nanomaterials that she’d want to bounce off Hiro. It was like an all in one package- a bubbly, happy best friend, _bubble tea_ , great ideas, and the gummy bear cupcakes. Hiro rubbed an eye as she excitedly described the use of the materials in medical imaging and _wouldn’t that be cool,_ when she stopped.

She adjusted her glasses, squinted at him, and talked again, her voice seemingly more serious and low, “Hiro, have you been sleeping?” Hiro shrugged, slurping more of the bubble tea, and she cocked a delicate eyebrow at him.

“I’m going to get Tadashi-“ and that was when the warning bells went off in Hiro’s head, blaring like no freaking tomorrow. “N-no, Honey, I’m going home in, like fifteen minutes!”

She had been skeptical, damn it, and she had always been amazing at picking out half baked lies, however seemingly bubbly Honey was. But, thankfully, she had left him off the hook.

His fingers stung slightly, five hours later, but he continued, even when a sudden cough wracked his thin frame, and he had to hold onto the desk for support. Hiro would have been almost done if his midsection hadn’t slammed into the desk, and he’d yelped, “Fuck, _ow_!” In no time, the familiar hissing sound came from the side of the lab, and soon enough Baymax had waddled over to him.

He gave him a weak grin. Baymax looked owlishly back at him. “You seem to be suffering from physical pain.”

Hiro waved him off. “Just my crappy balance, that’s it-“ Baymax had already scanned him up and down, and had said, somewhat curiously. “You are suffering from pyrexia, nasal congestion, increased mucus fluid, and a cough. The common cold.” The robot cocked its head at him. “This seems problematic, and requires bed rest.” And of freaking course, Baymax continued to say, “Audio calling Tadashi Hamada.”

Hiro managed to wrestle himself out of his chair, bouncing into Baymax’s soft vinyl form while whispering, “No, no, no, _no_ , he’ll flip if he finds out, abort call!”

Baymax, always loyal to his brother, did not listen, and Hiro gave up.

_“Hiro? Baymax called, is everything okay?”_

Hiro sank into the computer chair, tried not to groan. “Peachy keen over here. Marshmallow here-“ he glared at the robot who observed him interestedly, “-is overprotective. It’s all good, ‘Dashi.”

There was silence on the other end, and Hiro groaned. “What now?” Tadashi’s response, however, was soft, warm, and way too freaking nostalgic to be real. “ _You haven’t called me that since we were kids, you know?”_

Hiro blinked, then backtracked. Oh. It was true- the nickname had arose from a childish mispronunciation, but for the longest while after, he’d used it. Huh. Weird. “Stop going soft, I’m all fine. I’ll cuddle with Baymax if you want-“

And.

And his nose was prickling. His chest ached. Which only meant-

He was suddenly seized with a barrel of coughs, and it _hurt_ , like dull slices climbing up his ribs, snaking around his neck, choking him, and he couldn’t breathe. They rasped against his throat, hard, like a resonating drum, and it was only when he felt familiar arms envelop him that he managed to catch himself. He smiled, wry, leaned into Baymax’s warmth.

Tadashi’s voice fluttered in, half worried, half pissed _. “Hiro Hamada, what the hell? Are you sick? How long- when did it- Baymax?”_

Swearing was something Tadashi barely did, honestly, _he_ swore even more, so he was really, really screwed. Baymax, the traitor, answered. “Approximately a week, Tadashi.”

There was silence on the end for twelve seconds. Then-

“ _A week? And you didn’t tell me, bonehead? Wait, you’re you- why didn’t I notice? You’re coming home, Hiro. I’ll be there in five minutes.”_ Hiro didn’t argue at that point, because there wasn’t any arguing against his older brother in this mode. Tadashi would physically drag him out him out if he had to, only to swaddle him in blankets, and give him medically prescribed doses to his age because he was _such_ a nerd.

Soon enough, Tadashi had arrived, and drove him and Baymax’s carrying case in the moped, muttering under his breath in Japanese until he got Hiro to lie down. Hiro moaned suddenly, his head filling with sudden cotton balls, and Tadashi winced with him, running a few fingers down his forehead. “I’ll get some acetaminophen, okay?” Hiro could only snort at that, because it was _so_ much like his older brother to not just say Tylenol. Unfortunately, it only resulted in snot, gross, disgusting snot, and he moaned again.

Ugh.

Eventually, he’d been poked, prodded, fluffed, and at one point, Tadashi had unceremoniously stuck a thermometer in his mouth. His almond eyes creased as they read it, but he said nothing. Hiro had pathetically rolled himself in the tiniest of cocoons, and when Tadashi came back, he kneeled next to him. “Hey, Hiro, sit up, okay? Don’t want that big brain of yours hurting.” Hiro muffled a moan in the pillow, because his chest freaking _hurt_ , and all he wanted to do was sleep, but his brother’s gentle, strong arms coaxed him up.

Soon enough, he had taken the Tylenol, and Tadashi rolled him back up, setting a few pillows behind his head. “I’m not a baby, Tadashi,” Hiro protested, but Tadashi simply laughed, his eyes crinkling, warm and knowing. “You’re _my_ baby, Hiro, and don’t think about arguing. You know it’s true.” Hiro couldn’t help but groan, because yeah, it was. Aunt Cass had strolled in behind him, and perched on the side of his bed.

She set a few fingers on his  head, clicking her tongue at the heat that rose up to meet it. “You’re burning up, you know.” Hiro nodded, sank back into the pillow, and her face turned fond, like an old memory. “I’ll make some noodle soup tomorrow, alright? Is Tadashi taking care of you?” Hiro rolled his eyes, and nodded almost resignedly, which his brother chuckled at, before ruffling his hair gently. Aunt Cass set a kiss on his cheek before she skittered downstairs.

Hiro settled in the pillows, sighing, and closed his eyes. The Tylenol had taken effect and his chest had dulled to a slow burn, with his headache simmering in the background. Before he fell into a dream, he felt warm, chapped lips pressing against his forehead, and Tadashi’s voice murmuring, “Sleep, Hiro.”

And he did.

 

 

 

For four and a half hours.

 

Hiro blinked blearily, and forced out a breath of his congested nose, barely making out the scarlet _1:_ _47_ on his clock. His chest pain had decreased considerably, but his head felt like imploding, and he buried his ebony spikes in the pillow to combat it. He shivered, and _why the hell_ was he so cold? The pillows were warm beneath him, and he could feel the slow trickle of sweat on his forehead, yet the sensation whipped his veins into ice.

He shivered, his body trembling in the blankets, rustling for more heat. Hiro curled on himself, moaning when another bout of pain filled his head, muttering a tiny, fierce _crap_ as it did. His eyes shut into another fitful sleep and-

“Hiro?”

Of course. Of fucking course.

Tadashi stood next to his bed, hair askew, rubbing his eyes. “I heard you… everything alright?” His voice trickled into worry as Hiro curled away from him, trying to conserve body heat. He felt Tadashi’s fingers gently skim his forehead, and looked back only to find his almond eyes wide. “Your fever’s gone up.”

Hiro wanted to laugh, despite the sweat draping his face in a light sheen, despite the fact his head felt like exploding, despite the fact he was _trying_ to stay warm. His voice, slightly nasally from his stupid stuffy nose, said, “I-I’m frickin’ _freezing_ , Tadashi.” Tadashi’s eyes narrowed slightly, and he turned, as if he was thinking, and Hiro curled away, because another blanket wasn’t going to help his stupid cold.

Stupid cold.

Stupid headache.

Stupid decisions, _ugh_!

Suddenly, there was a warmth curled around his spine, like a protective shell, arms secured round his torso, and a hand in his hair. His eyes widened, because it was so familiar that he’d documented it long ago, when he’d snuggle with Tadashi on stormy nights and during crappy movies. Heat seeped in slowly, but surely, and he sighed, even through his chest shuddered slightly. He muttered, turning toward his brother, “You’re going to get sick, you know. Don’t blame me.”

Tadashi’s tired chuckle was like a drizzle of rain. “An increase in body heat has been proven to kill off bacteria faster. You need it.” He settled his fingers in Hiro’s hair, gently, gently carding through it, and if Hiro leaned in he could make out the slightest tang of machine oil. It was mixed with something misty, something so uniquely _Tadashi_ that Hiro could only snuggle his head into his brother’s neck further.

“ _Call_ me next time, Hiro, please. You’re a terrible patient.” Tadashi’s voice was teasing, but held a note of earnestness, and Hiro managed to laugh, reverberating hard in his stomach.

“Okay, ‘Dashi, but I think Baymax would disagree.” He could almost feel the burn of his brother’s brilliant grin. Their bedroom softened, turning slowly into darkness, the feeling of his brother’s arms constant, the scent of him like a warm blanket Hiro never wanted to take off. Tadashi didn’t say anything in the silence, but brushed a light kiss near his hair, right above his left eyebrow.

“I’ll be here in the morning, okay, _Otōto_?” But Hiro had already drifted, his light breaths intermingling with the muted lullaby of San Fransokyo traffic, clear and comforting. Tadashi smiled softly, settling his face in the crook of his little brother’s shoulder, and soon, his snores had joined his. 

 


End file.
